Conventional padlocks cooperating with an associated hasp to secure doors, equipment, storage spaces, etc., have proven unsatisfactory in preventing unauthorized access to the enclosed area and in securing equipment. The designs of prior art padlocks lend themselves to being defeated by cutting and prying tools. Even when used in cooperation with conventional shields, shrouds, and/or enclosures, the prior art padlock has not been seen to thwart a determined thief's successful access to the supposedly secured space. Padlocks generally fit very loosely within a hasp affording easy insertion of prying or cutting tools to break the lock. The loose fit also fails to keep the closure itself closed tightly when the lock serves also to latch the closure.
Most padlocks have a double post shackle requiring a complex locking bolt mechanism with two openings to receive the shackle. The normally "U" shaped shackle attached to the locking bolt limits the application of the normal padlock in terms of accessibility to the hasp.
Most prior art shielded padlocks are limited in their application because the shield utilized must be permanently mounted to the structure to be secured as a result of either its massive shape or inherent limitations in its deign, thereby inhibiting both the transferability and use of the shield in other locations.
Those prior art shielded lock assemblies which are not permanently fixed to a wall or door are generally comprised of a modified piece added to an existing conventional lock for use with a specifically identifiable hasp, and are generally incapable of cooperating with other existing conventional hasps of differing sizes and shapes.
Constructing prior art shields out of high strength alloy steels and other special materials in order to impair the effectiveness of conventional cutting and prying tools has considerably increased the cost of prior art shielded locks while generally doing little to prevent the undesired unauthorized access.
Prior art shielded locks generally fail to provide any additional means for improving the locking engagement between the padlock and the hasp except for simply enclosing the lock and hasp itself.